Attached earlobes are a recessive trait in humans. In the tree below, people with attached earlobes are shaded in. Which best describes the person
labeled X in the tree?
A. A female with no recessive alleles
B. A male with no recessive alleles
C. A male with one recessive allele
D. A female with one recessive allele

It would be C

Explanation:

If you look at the tree you can see that one of the male's parents had the recessive allele, and one of the siblings has the ressive allele, the means the male could have the trait but isnt showing it.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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